Rhodium-Catalyzed Reductive Coupling of Disulfides and Diselenides with Alkyl Halides, Using Hydrogen as a Reducing Agent
作者:Kaori Ajiki、Masao Hirano、Ken Tanaka
DOI:10.1021/ol051588n
日期:2005.9.1
[reaction: see text] We have established that RhCl(PPh3)3 catalyzes a reductive coupling of disulfides and diselenides with alkyl halides in the presence of triethylamine using hydrogen as a reducing agent. This reaction serves as a convenient new method to produce unsymmetrical sulfides and selenides from disulfides and diselenides instead of unstable and odoriferous thiols and selenols.
Investigation of steric and electronic effects in the copper-catalysed asymmetric oxidation of sulfides
作者:Graham E. O'Mahony、Kevin S. Eccles、Robin E. Morrison、Alan Ford、Simon E. Lawrence、Anita R. Maguire
DOI:10.1016/j.tet.2013.08.063
日期:2013.11
in the copper-catalysed asymmetricoxidation of aryl benzyl, aryl alkyl and alkyl benzyl sulfides have been investigated. The presence of an aryl group directly attached to the sulfur is essential to afford sulfoxides with high enantioselectivities, with up to 97% ee for 2-naphthyl benzyl sulfoxide, the highest enantioselectivity achieved to date for copper-catalysed asymmetric sulfoxidation. In contrast
Reductive Coupling of Disulfides and Diselenides with Alkyl Halides Catalysed by a Silica-Supported Phosphine Rhodium Complex using Hydrogen as a Reducing Agent
作者:Hean Zhang、Mangen Hu、Mingzhong Cai
DOI:10.3184/174751913x13796950361813
日期:2013.10
The reductive coupling of disulfides and diselenides with alkyl halides was achieved in THF at 65 °C in the presence of 3 mol% of a silica-supported phosphine rhodium complex and triethylamine using hydrogen as a reducing agent, affording a variety of unsymmetrical sulfides and selenides in high yields. The heterogeneous rhodium catalyst can be recovered by a simple filtration and reused several times
在 3 mol% 二氧化硅负载的膦铑配合物和三乙胺存在下,使用氢气作为还原剂,在 65 °C 的 THF 中实现二硫化物和二硒化物与烷基卤化物的还原偶联,得到各种不对称的硫化物和硒化物高产。多相铑催化剂可以通过简单的过滤回收并重复使用多次而不会显着损失活性。还观察到与酰卤的反应。
Photochemical Functionalization of Heterocycles with EBX Reagents: C−H Alkynylation versus Deconstructive Ring Cleavage**
作者:Errika Voutyritsa、Marion Garreau、Maroula G. Kokotou、Ierasia Triandafillidi、Jérôme Waser、Christoforos G. Kokotos
DOI:10.1002/chem.202002868
日期:2020.11.11
The development of novel methodologies for the functionalization of saturated heterocycles is highly desirable. Herein, we report a cheap and efficient photochemical method for the C−H functionalization of saturated O‐heterocycles, as well as the deconstructive ring‐cleavage of S‐heterocycles, employing hypervalent iodine alkynylation reagents (ethynylbenziodoxolones, EBX). This photochemical alkynylation
carried out under transition-metal-free conditions, showing yields of asymmetric sulfides higher than 80%. Tertiary alkyl halides and aryl halides do not react with thiourea under formation of the corresponding isothiouroniumsalts; however, 5-bromopyrimidine and 2-bromopyrimidine lead to yields of 79.2% and 87.6%, respectively. This method is of significant importance from the both environmental and economic